Demonstrable correctness and maintainability should come first ... My reply was addressing what could be seen as a "speed first" approach to coding being advocated

Strongly agree! See: on Code Optimization

Sadly, there seems to have been an increase lately in monks asking for faster code without explaining why speed matters for their problem and without providing a benchmark. Some reacted appallingly on being given your well-meaning advice, one even deleting all his content and leaving the monastery in a huff.